namespace System.util.zlib;

internal sealed class StaticTree
{
    /// <summary>
    ///     Bit length codes must not exceed MAX_BL_BITS bits
    /// </summary>
    internal const int MAX_BL_BITS = 7;

    private const int BlCodes = 19;
    private const int DCodes = 30;
    private const int LCodes = Literals + 1 + LengthCodes;
    private const int LengthCodes = 29;
    private const int Literals = 256;
    private const int MaxBits = 15;

    internal static readonly StaticTree StaticBlDesc;

    internal static readonly StaticTree StaticDDesc;

    internal static readonly short[] StaticDtree =
    {
        0, 5, 16, 5, 8, 5, 24, 5, 4, 5,
        20, 5, 12, 5, 28, 5, 2, 5, 18, 5,
        10, 5, 26, 5, 6, 5, 22, 5, 14, 5,
        30, 5, 1, 5, 17, 5, 9, 5, 25, 5,
        5, 5, 21, 5, 13, 5, 29, 5, 3, 5,
        19, 5, 11, 5, 27, 5, 7, 5, 23, 5,
    };

    internal static readonly StaticTree StaticLDesc;

    internal static readonly short[] StaticLtree =
    {
        12, 8, 140, 8, 76, 8, 204, 8, 44, 8,
        172, 8, 108, 8, 236, 8, 28, 8, 156, 8,
        92, 8, 220, 8, 60, 8, 188, 8, 124, 8,
        252, 8, 2, 8, 130, 8, 66, 8, 194, 8,
        34, 8, 162, 8, 98, 8, 226, 8, 18, 8,
        146, 8, 82, 8, 210, 8, 50, 8, 178, 8,
        114, 8, 242, 8, 10, 8, 138, 8, 74, 8,
        202, 8, 42, 8, 170, 8, 106, 8, 234, 8,
        26, 8, 154, 8, 90, 8, 218, 8, 58, 8,
        186, 8, 122, 8, 250, 8, 6, 8, 134, 8,
        70, 8, 198, 8, 38, 8, 166, 8, 102, 8,
        230, 8, 22, 8, 150, 8, 86, 8, 214, 8,
        54, 8, 182, 8, 118, 8, 246, 8, 14, 8,
        142, 8, 78, 8, 206, 8, 46, 8, 174, 8,
        110, 8, 238, 8, 30, 8, 158, 8, 94, 8,
        222, 8, 62, 8, 190, 8, 126, 8, 254, 8,
        1, 8, 129, 8, 65, 8, 193, 8, 33, 8,
        161, 8, 97, 8, 225, 8, 17, 8, 145, 8,
        81, 8, 209, 8, 49, 8, 177, 8, 113, 8,
        241, 8, 9, 8, 137, 8, 73, 8, 201, 8,
        41, 8, 169, 8, 105, 8, 233, 8, 25, 8,
        153, 8, 89, 8, 217, 8, 57, 8, 185, 8,
        121, 8, 249, 8, 5, 8, 133, 8, 69, 8,
        197, 8, 37, 8, 165, 8, 101, 8, 229, 8,
        21, 8, 149, 8, 85, 8, 213, 8, 53, 8,
        181, 8, 117, 8, 245, 8, 13, 8, 141, 8,
        77, 8, 205, 8, 45, 8, 173, 8, 109, 8,
        237, 8, 29, 8, 157, 8, 93, 8, 221, 8,
        61, 8, 189, 8, 125, 8, 253, 8, 19, 9,
        275, 9, 147, 9, 403, 9, 83, 9, 339, 9,
        211, 9, 467, 9, 51, 9, 307, 9, 179, 9,
        435, 9, 115, 9, 371, 9, 243, 9, 499, 9,
        11, 9, 267, 9, 139, 9, 395, 9, 75, 9,
        331, 9, 203, 9, 459, 9, 43, 9, 299, 9,
        171, 9, 427, 9, 107, 9, 363, 9, 235, 9,
        491, 9, 27, 9, 283, 9, 155, 9, 411, 9,
        91, 9, 347, 9, 219, 9, 475, 9, 59, 9,
        315, 9, 187, 9, 443, 9, 123, 9, 379, 9,
        251, 9, 507, 9, 7, 9, 263, 9, 135, 9,
        391, 9, 71, 9, 327, 9, 199, 9, 455, 9,
        39, 9, 295, 9, 167, 9, 423, 9, 103, 9,
        359, 9, 231, 9, 487, 9, 23, 9, 279, 9,
        151, 9, 407, 9, 87, 9, 343, 9, 215, 9,
        471, 9, 55, 9, 311, 9, 183, 9, 439, 9,
        119, 9, 375, 9, 247, 9, 503, 9, 15, 9,
        271, 9, 143, 9, 399, 9, 79, 9, 335, 9,
        207, 9, 463, 9, 47, 9, 303, 9, 175, 9,
        431, 9, 111, 9, 367, 9, 239, 9, 495, 9,
        31, 9, 287, 9, 159, 9, 415, 9, 95, 9,
        351, 9, 223, 9, 479, 9, 63, 9, 319, 9,
        191, 9, 447, 9, 127, 9, 383, 9, 255, 9,
        511, 9, 0, 7, 64, 7, 32, 7, 96, 7,
        16, 7, 80, 7, 48, 7, 112, 7, 8, 7,
        72, 7, 40, 7, 104, 7, 24, 7, 88, 7,
        56, 7, 120, 7, 4, 7, 68, 7, 36, 7,
        100, 7, 20, 7, 84, 7, 52, 7, 116, 7,
        3, 8, 131, 8, 67, 8, 195, 8, 35, 8,
        163, 8, 99, 8, 227, 8,
    };

    internal readonly int Elems;
    internal readonly int ExtraBase;

    internal readonly int[] ExtraBits;

    // extra bits for each code or null
    // base index for extra_bits
    // max number of elements in the tree
    internal readonly int MaxLength;

    internal readonly short[] static_tree;
    // static tree or null
    // max bit length for the codes

    static StaticTree()
    {
        StaticBlDesc = new StaticTree(null, Tree.ExtraBlbits, 0, BlCodes, MAX_BL_BITS);
        StaticDDesc = new StaticTree(StaticDtree, Tree.ExtraDbits, 0, DCodes, MaxBits);
        StaticLDesc = new StaticTree(StaticLtree, Tree.ExtraLbits, Literals + 1, LCodes, MaxBits);
    }

    internal StaticTree(short[] staticTree,
                        int[] extraBits,
                        int extraBase,
                        int elems,
                        int maxLength
    )
    {
        static_tree = staticTree;
        ExtraBits = extraBits;
        ExtraBase = extraBase;
        Elems = elems;
        MaxLength = maxLength;
    }
}